Go to your physical therapist. If you don't allready have one, find one you like because you will be using him/her for the rest of your life if you like skiing.
For me, it was as simple as stretching every night and every morning and working out on a spinner bike and using the leg press machine at the gym. My knees are doing fine now, and two years ago I was having trouble walking up stairs.
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'Today I washed my shirt with my washboard abs. I didn't even have to take it off, I just poured water on the stain and scrubbed it on my abs.' (My little brother)
'I'm in his nigger crew' (my little brother in response to my statement that he was in my 'digger crew')
'My knee hurts' (Jeff Merat after grinding a lunch table for an hour instead of sitting in the ski patrol shack for his torm mcl and acl which he got earlier that day.)
'I'm not asking for any help, just maybe for you to get off your ass.'(my dad)